diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2023-03-05 11:27:48 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2023-03-05 11:27:48 -0800 |
| commit | 7f9ec7d8169b5281eff2b907d8ffb1bf56045f73 (patch) | |
| tree | a48e3363789751bf9df08caf409248e04a9ce0c3 /drivers | |
| parent | 4e9c542c7a51bcc8f6ce283459900ba47a6690f5 (diff) | |
| parent | dd093fb08e8f8a958fec4eef36f9f09eac047f60 (diff) | |
Merge tag 'x86-urgent-2023-03-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 updates from Thomas Gleixner:
"A small set of updates for x86:
- Return -EIO instead of success when the certificate buffer for SEV
guests is not large enough
- Allow STIPB to be enabled with legacy IBSR. Legacy IBRS is cleared
on return to userspace for performance reasons, but the leaves user
space vulnerable to cross-thread attacks which STIBP prevents.
Update the documentation accordingly"
* tag 'x86-urgent-2023-03-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
virt/sev-guest: Return -EIO if certificate buffer is not large enough
Documentation/hw-vuln: Document the interaction between IBRS and STIBP
x86/speculation: Allow enabling STIBP with legacy IBRS
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/virt/coco/sev-guest/sev-guest.c | 20 |
1 files changed, 17 insertions, 3 deletions
diff --git a/drivers/virt/coco/sev-guest/sev-guest.c b/drivers/virt/coco/sev-guest/sev-guest.c index 4ec4174e05a3..7b4e9009f335 100644 --- a/drivers/virt/coco/sev-guest/sev-guest.c +++ b/drivers/virt/coco/sev-guest/sev-guest.c @@ -377,9 +377,26 @@ static int handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_code, in snp_dev->input.data_npages = certs_npages; } + /* + * Increment the message sequence number. There is no harm in doing + * this now because decryption uses the value stored in the response + * structure and any failure will wipe the VMPCK, preventing further + * use anyway. + */ + snp_inc_msg_seqno(snp_dev); + if (fw_err) *fw_err = err; + /* + * If an extended guest request was issued and the supplied certificate + * buffer was not large enough, a standard guest request was issued to + * prevent IV reuse. If the standard request was successful, return -EIO + * back to the caller as would have originally been returned. + */ + if (!rc && err == SNP_GUEST_REQ_INVALID_LEN) + return -EIO; + if (rc) { dev_alert(snp_dev->dev, "Detected error from ASP request. rc: %d, fw_err: %llu\n", @@ -395,9 +412,6 @@ static int handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_code, in goto disable_vmpck; } - /* Increment to new message sequence after payload decryption was successful. */ - snp_inc_msg_seqno(snp_dev); - return 0; disable_vmpck: |